Essential oil blend (ESOB) containing Zingiber montanum or Phlai and Zingiber tenuiscapus oils as the major components has high levels of terpenes such as sabinene, terpinene, terpinolene, and terpine-4-ol. Phlai is well known for its analgesic property, but its effects on mood remain unclear. This study aimed to investigate the acute effects of inhaling the ESOB containing phlai essential oils on mood and stress among healthy volunteers.
A prospective, randomized, double-blinded, controlled trial pilot study was conducted among 38 healthy male volunteers; 19 in the ESOB containing phlai oil group and 19 in the control group, which used olive oil. One single inhalation was provided continuously for 15 min via hot steam. Mood status was assessed pre- and post-intervention using the Visual Analog Scales for Mood, Anxiety, Stress and Alertness (MASA). Rorschach tests, in a modified analysis, were also employed. One-way ANCOVA was used to determine statistical differences of the mood test results between ESOB containing phlai oil and olive oil.
Mean age of the participants was 22.11 (SD 2.1) years. Both ESOB containing phlai oil and olive oil increased the post-test scores of positive mood and reduced the scores of negative mood. However, no difference was observed regarding the mood test scores between groups, except concerning the Rorschach stress test (F (1,38)=6.486, p=0.015). The variance of change, explained by the model (R square), was 32.8%, while the adjusted R-squared was 0.290.
Single inhalation aromatherapy using ESOB containing phlai oil or olive oil showed an immediate improvement of mood states among healthy young male volunteers by easing the negative emotions and enhancing positive emotions, especially feelings of pleasure and contentment. Natural blend of phlai essential oils was more efficacious than olive oil in reducing emotional stress.
The authors would like to acknowledge the Department of Thai Traditional and Alternative Medicine, Ministry of Public Health, Thailand for the funding support to carry out this research under the Northern Herbs Innovation Park Project in 2016.
Author contributions: WA, SG, SC, TW, PV, and NW designed the conceptualization. WA, SG, SC, TW, PV, and NW collected and made data cleansing. WA, TW, and NW analyzed and interpreted the data and were major contributors in writing the manuscript. All authors read and approved the final manuscript.
Research funding: The research was funded by the Ministry of Public Health, Thailand under the Northern Herbs Innovation Park Project in 2016.
Employment or leadership: None declared.
Honorarium: None declared.
Competing interests: The funding organization(s) played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
 Wotman M, Levinger J, Leung L, Kallush A, Mauer E, Kacker A. The efficacy of lavender aromatherapy in reducing preoperative anxiety in ambulatory surgery patients undergoing procedures in general otolaryngology. Laryngoscope Invest Otolaryngol 2017;2:437–41.Search in Google Scholar
 Sánchez-Vidaña DI, Ngai SP, He W, Chow JK, Lau BW, Tsang HW. The effectiveness of aromatherapy for depressive symptoms: a systematic review. Evid Based Complement Altern Med 2017;2017:5869315.Search in Google Scholar
 Tisserand R, Balacs T. Essential oil safety: a guide for health care professionals. Edinburgh, UK: Churchill Livingstone, 1995.Search in Google Scholar
 Clarke S. Essential chemistry for aromatherapy, 2nd ed. China: Churchill Livingstone Elsevier, 2008.Search in Google Scholar
 Price S, Price L. Aromatherapy for health professionals, 4th ed. London: Churchill Livingstone Elsevier, 2012.Search in Google Scholar
 Matsumoto T, Asakura H, Hayashi T. Effects of olfactory stimulation from the fragrance of the Japanese citrus fruit yuzu (Citrus junos Sieb. ex Tanaka) on mood states and salivary chromogranin A as an endocrinologic stress marker. J Altern Complement Med 2014;20:500–6.Search in Google Scholar
 Conrad P, Adams C. The effects of clinical aromatherapy for anxiety and depression in the high risk postpartum woman — a pilot study. Complement Ther Clin Pract 2012;18:164–8.Search in Google Scholar
 Chongmelaxme B, Sruamsiri R, Dilokthornsakul P, Dhippayom T, Kongkaew C, Saokaew S et al. Clinical effects of Zingiber cassumunar ( Plai ): a systematic review. Complement Ther Med 2017;35:70–7.Search in Google Scholar
 Panthong A, Kanjanapothi D, Niwatananun V, Tuntiwachwuttikul P, Rewtrakul V. Anti - inflammatory activity of compounds isolated from Zingiber cassumunar. Planta Med 1990;56:655.Search in Google Scholar
 Ozaki Y, Kawahara N, Harada M. Anti-inflammatory effect of Zingiber cassumunar Roxb. and its active principles. Chem Pharm Bull (Tokyo) 1991;39:2353–6.Search in Google Scholar
 Masuda T, Jitoe A, Mary T. Isolation and structure determination of cassumunarins A, B, and C: new anti – inflammatory Antioxidants from a tropical ginger, Zingiber cassumunar. J Am Oil Chem’ Soc 1995;72:1053–7.Search in Google Scholar
 Yonkers KA, O’Brien PM, Eriksson E. Premenstrual syndrome. Lancet 2008;371:1200–10.Search in Google Scholar
 Chow S-C, Shao J, Wang H. Sample size calculations in clinical research, 2nd ed. Boca Raton, FL: Chapman & Hall / CRC, 2003.Search in Google Scholar
 Cocks K, Torgerson DJ. Sample size calculations for pilot randomized trials: a confidence interval approach. J Clin Epidemiol 2013;66:197–201.Search in Google Scholar
 Arpornchayanon W, Sriphadungamphai W, Hanprasertpong N, Chaiyasate S. A comparison of the inhaling effects of eucalyptus versus shallot in hot steam on nasal congestion in acute rhinitis. J Thai Tradit Altern Med 2017;15:92.Search in Google Scholar
 Rorschach H. Rorschach test – psychodiagnostic plates. Cambridge, MA: Hogrefe Publishing Corp, 1927.Search in Google Scholar
 Van Breukelen GJ. ANCOVA versus change from baseline had more power in randomized studies and more bias in nonrandomized studies. J Clin Epidemiol 2006;59:920–5.Search in Google Scholar
 Ali B, Al - Wabel NA, Shams S, Ahamad A, Khan SA, Anwar F. Essential oils used in aromatherapy: a systemic review. Asian Pac J Trop Biomed 2015;5:601–11.Search in Google Scholar
 Setzer WN. Essential oils and anxiolytic aromatherapy. Nat Prod Commun 2009;4:1305–16.Search in Google Scholar
 Diego MA, Jones NA, Field T, Hernandez-Reif M, Schanberg S, Kuhn C et al. Aromatherapy positively affects mood, EEG patterns of alertness and math computations. Int J Neurosci 1998;96:217–24.Search in Google Scholar
 Konno N. Mental caring for pre symptomatic depression by aroma — effects of lemon and yuzu essential oil. Aroma Res 2009;39:260–3.Search in Google Scholar
© 2019 Walter de Gruyter GmbH, Berlin/Boston